adnation|ædˈneɪʃən| [n. of action f.prec.; see -ion1.] Attachment of surfaces; growth to. esp. in Bot. Adhesion of different whorls of the inflorescence to each other. 1842Gray Struct.Bot. vi. §3 (1880) 179 Union of contiguous parts of different circles [of the inflorescence]= Adnation.